1. Field of the Invention
The invention disclosed in this specification relates to a semiconductor device using a semiconductor element and a method for manufacturing the semiconductor device.
2. Description of the Related Art
A technique by which a transistor is formed using a semiconductor thin film formed over a substrate having an insulating surface has been attracting attention. Such a transistor is applied to a wide range of electronic devices such as an integrated circuit (IC) or an image display device (display device). A technique in which a wide-gap semiconductor such as an oxide semiconductor is used for a semiconductor thin film that can be applied to a transistor has been attracting attention.
For example, Patent Document 1 discloses that an amorphous oxide semiconductor film including an In—Ga—Zn—O-based oxide can be used for a channel formation region of a thin film transistor.